Alice Gross
Builder Arnis Zalkalns is suspected of Alice Gross's disappearanceMet Police

Scotland Yard detectives searching for missing teenager Alice Gross have named convicted murderer Arnis Zalkalns as a suspect in her disappearance.

The 41-year-old, who served a seven-year murder sentence in native Latvia, was seen on CCTV cycling along Brentford Lock at 4pm, some 15 minutes after Alice walked the same route the day she disappeared on 28 August.

Detectives believe he is likely to have come across Alice as they were both going in the same direction, north along the canal towpath. What, if anything, happened there is now one of the focuses of this investigation.

The builder was last seen at his home in Ealing on the evening of Wednesday 3 September and has not accessed his bank account or used his mobile phone since.

His passport was left at his house but friends and family of Zalkalns have told police his disappearance is out of character and concern is growing over his whereabouts.

Police have received 100 calls about the disappearance since last week and have offered a reward of up to £20,000 for anyone who has information that leads detectives to find Alice.

The last sighting of the 14-year-old schoolgirl was at 4.26pm on 28 August when she was caught on CCTV on Trumpers Way, the bridge that crosses the Grand Union Canal, as she seemingly made her way towards her home in Hanwell, west London.

Alice texted her father asking if he was at home because she had forgotten her house key in her final iPhone message before going missing.

The text, which was sent an hour and a half before she disappeared, suggests Alice was planning to return home after she went for a walk.

Her discarded rucksack was found on a path beside the River Brent on 2 September.

Alice is white, 5ft 2ins tall and of very slim build with shoulder-length, light brown hair. When she left home that day she was wearing dark blue jeans and a grey top, and tartan framed glasses. She was carrying a dark rucksack, and wearing denim blue 'Vans' shoes, these shoes were in her rucksack when it was found by police on 2 September.

Zalkalns is white, 5ft 10ins, of stocky build and with dark brown hair, which he normally wears tied in a pony tail. He usually cycles to work, and rides a red Trek Mountain Bike and a racing bike.

Anyone with any information is asked to contact the investigation team on 020 8358 0100, or call Crimestoppers anonymously on 0800 555 111.